The 2018 All-Ireland hurling championship was expected to be memorable, and for many, it more than lived up to that hype. The main generator of this excitement prior to the championship was a radically different format, which replaced the provincial knockout format with a round robin, added a new tier to enable more competitive matches for teams previously in the Leinster round robin stage, and dramatically shortened the amount of time in which all these extra matches were to take place. The new format ensured multiple home matches for (nearly) all teams, a increase from a minimum 2 games to a minimum of 4 games before a team could see their season finish.

With the dust now settled, it appears that the general consensus was very positive. It seems to be confirmed that we are witnessing an unusually competitive era: We now have our 5th different champion in 6 years, with Limerick breaking a 45 year drought. The final was won by a single point, following up on two semi finals which both went to extra time, and one of which went to a replay. In Munster, even the eventual champions could only finish third, while the previous league and All-Ireland runners up, Tipperary and Waterford, failed to win a single match. Leinster also had its fair share of excitement, with four round robin games ending with a single score margin, and the final itself going to a replay.

The new format was not perfect, with many taking issue with the excessive frequency of matches without a break for certain teams, or finding it jarring that the final took place in the middle of August. The rapid pace of the round robin stages was exciting, but many found it hard to follow, as television only covered a certain percentage of games, and clashes in schedules meant people had to pick and choose which matches to attend.

All in all, however, a very memorable year. But was it truly as exceptional as many people feel it was? In this article, we’ll delve into the stats and figures behind the sentiment, and explore why it truly was a great championship in 2018, as well as where it was prevented from being perfect.

Note that, unless stated otherwise, the following figures include the Joe McDonagh championship as part of the All-Ireland, as well as the Munster and Leinster championships, since places in the knockout stages of the All-Ireland could be earned from all of these groups.

Overall scoring

One of the key elements that people highlighted from this year’s championship was the high scoring; it certainly felt like teams were putting up more points than usual, but does this hold up?

It certainly does. The chart above highlights that this was the highest scoring All-Ireland championship since the current scoring format was introduced in 1896: On average, each team scored 24.6 points per match. This narrowly beats out the previous record of 24.5 points per match, achieved in the 2017 championship. It also contained the highest number of white flags, with each team getting an average of 20.2 points per match, again beating the record set the year before, which had 19.5 points per match.

As well as being the highest scoring on average, it also included the highest scoring individual championship match: the semi final between Cork and Limerick, which went to extra time, finished with an enormous scoreline of 2-31 to 3-32, a total of 78 points between the two teams. There were two other matches in this year’s championship which appear in the top 10 highest scoring championship games of all time; The day before the Cork/Limerick semi final, Clare and Galway put up 1-30 apiece for a total of 66 points, which Meath and Antrim had a 64 point game during the Joe McDonagh championship.

However, high scoring on its own does not make exciting games: That top 10 list had an average winning margin of almost 20 points; the vast majority of these games were total hammerings. The 2018 championship, however, added scoring without removing competitiveness:

Of the championships studied, the 2018 All-Ireland had the 14th narrowest average winning margin, with the average match finishing with teams separated by 6.4 points. Only 2 championships have had closer average matches within the last 30 years, in 2001 and 1991. This appears to be a success of the new format; Increasing the number of games in Munster, and splitting Leinster into Leinster and the Joe McDonagh, meant that every team had matches against teams at their own level. It’s no longer possible for teams to get lucky draws against weaker teams, propelling them further into the championship than they should be.

Offensive and defensive ratings

The offensive and defensive ratings of teams is simply a measure of how much they scored and conceded per match. It’s not a perfect measure, as it can be dramatically affected if teams play considerably easier or tougher opponents during the competition, but it can give a rough idea of how well each team performs offensively and defensively.

Only the Munster and Leinster teams were focused on for this, as it made it easier to compare with previous years; many of the Joe McDonagh teams played in the Christy Ring rather than the All-Ireland in recent years. Historically, they are also the 10 most competitive teams, and comprise of all the teams who have won multiple All-Ireland championships.

The above chart displays how much each team in Munster and Leinster scored (offensive rating) and conceded (defensive rating) per match. With the exception of Offaly, every other team is in a very tight cluster, showing just how little separated the top teams this year. A more detailed table is provided below:

It’s also notable that there was no team that was top 3 in both offense and defense: Looking at the same 10 teams, there has only been one year in the previous 10 championships where neither finalist accomplished this feat. This occured in 2013, but even in that year, the eventual winners Clare were so far ahead of the pack offensively (they scored 27 points per game, 4 points more per match than the next best team that year), that their mediocre defense (rated 6th out of 10, conceding 20.9 points per game) barely mattered.

In contrast, Limerick were 2nd offensively and 5th defensively, while Galway were 4th offensively and 2nd defensively. Not only did neither finalist finish in the top 3 in both categories, they didn’t even perform the best in either category; Cork were the strongest offensively, scoring a huge 29.3 points per game, while Wexford were the best defensive team, conceding only 21 points per game.

Looking only at average scoring margin, the finalists were more in line with previous years, as the finalists had the best results; Limerick had the best average scoring margin, winning by 4.9 points per game on average, while Galway were second with 4.1 points per game more than their opponent. However, yet again, 2018 was exceptionally close; looking at the average scoring margin in each year since 2009, Limerick had the lowest margin to top the table for a given year. Again, the next closest was 2013, where Clare had the best average scoring margin, winning by an average of 6.1 points per match. The largest average margin over the last 10 years was Kilkenny in 2015, where they won by 10.3 points per game.

The gallery below displays the offensive and defensive ratings for these 10 teams in each of the previous 9 championships.

Once more, it is clear how unusual this year was; the typical championship has a relatively straight line from best to worst, with maybe a handful of teams clustered near the top or bottom. Looking back at the chart for 2018 at the start of this section, this year had one big cluster, with only Offaly as an outlier. There has been much debate about their relegation from Leinster to the 2019 Joe McDonagh championship, but this chart does hint at why this might be appropriate, given their performance. Every one of the other 9 teams, though, could point to matches where an extra goal, or even point, could have made an enormous difference to how their championship ended.

Scores over time

The final score rarely captures the mood of a game. Depending on how the score swung throughout the match, a six point win can sometimes feel like a hammering, and other times like a lucky, last minute escape. The charts below divide the games into 10 minute slices, and show how much each team scored and conceded, on average, in each period.

These charts give us an idea of how teams performed over the course of matches. Though there are cases where the averages flatten out the results (Cork had many volatile games, with big swings in scores, but because these occurred at different points in each game, their chart looks very steady), all in all, it gives an idea of when different teams fall off or pick up the pace.

Each chart tells its own story:

In the Joe McDonagh, the winners, Carlow, didn’t start the tournament well, but came through to win it all. Their chart (with its overall winning margin damaged by their heavy defeat to eventual champions, Limerick), shows a scrappy team who are able to cling on, them come back strong to win games at the death. In contrast, the runners up, Westmeath, are steady for most of the match, eking out a small lead, before conceding a bit too much right at the end. Other competitive teams within the Joe McDonagh, Antrim and Kerry, both displayed a strong second half, but often got into a bad deficit early, hurting their chances to win.

In Munster, Clare look extremely volatile. It seemed that while they were strong offensively, they were prone to streaky defense. The end result is a very up-and-down line, which trends upwards, but captures their habit of rescuing games in the final minutes; they came back from a losing position with very little time left to win against Tipperary in Munster and to draw against Galway in the first semi final. Their luck finally ran out against Galway in the replay, but not after they pushed the game to a single point after being down by a large margin early on.

Cork, as mentioned, had many streaky games, but the chart has flattened out somewhat, as these didn’t occur at the same points in each match. However, it is clear that, while they won matches overall, they had very fine margins. Unsurprising, for a team that drew two of their games in Munster. Though a strong team, these small margins and their inconsistency caught up to them against Limerick in the semi final, as they weren’t able to maintain their lead coming into the end of the match and through extra time.

Limerick’s graph highlights why they were this year’s champions. Like Cork, they typically got off to a strong start and held it. Unlike Cork, however, their average performance saw them hold a lead of 4-5 points, as opposed to Cork’s average of just a single point. Though their average lead doesn’t increase as quickly later as it does in those early minutes, it stays gradually trending upwards for the rest of the match, displaying their strong bench.

Tipperary’s chart is a mirror image of Cork’s: They got into narrow deficits early, and couldn’t quite get back into games. Similar to Cork, their typical games were far more streaky, but the chart flattens this out. Though they had poor results to finish the year, the margins between them being very competitive and what actually happened were tiny: though they crashed out with no wins in Munster, scoring 5 extra points, or conceding 5 fewer, across 3 of their games would have been enough for them to top the table. It should surprise nobody if Tipperary come back strong next year, as with even a slight improvement should see them in a much better position.

Waterford had a season plagued by injury, and heavily underperformed as a result. The chart doesn’t flatter their performances; through sheer effort they could display good starts to each half, but their disadvantages would soon catch up to them, putting them firmly in last place in a highly competitive group.

In Leinster, Dublin do not at all look like a team who lost 3 out of 4 games. Like Tipperary, their losses were all fine margins, losing by two to Kilkenny and Wexford and by one to Galway. Their chart gets heavily skewed by their one win; a 17 point steamrolling of Offaly. However, even with the heavy skew created by this match, the reason they failed to pick up more wins shines through; though steady in the first half, and strong in most of the second, Dublin consistently fell apart in the final minutes of the game, conceding 3 points more than they scored, on average, in the final 10 minutes. With every loss coming by fewer than three points, it's fair if Dublin felt hard done by in Leinster this year.

Galway’s chart provides some evidence for a complaint many pundits had about their performances this year; they would lead heavily after about 20 minutes, and finish the game strongly in the final 20, but would fall off badly in between, allowing the other team back into it. Though undefeated until the final, Galway had to play two replays, and two more matches won by only a point. Many felt that Galway should have been more dominant throughout their matches, and it finally caught up to them in the final; when they failed to deliver in the opening 20 minutes, Galway found themselves in just too deep a hole to claw their way out, losing by a single point despite another strong finish.

Though it was expected to be a rebuilding year, Kilkenny came in to the All-Ireland with strong expectations after winning the league. The chart conveys their current position quite well, as a team that’s not quite there yet, but is close to being very competitive again. In a typical match, they would struggle out of the blocks, but steadily and consistently fight their way back through the remainder of the match. Though not a reliable situation, and one that failed them in their final two matches against Galway and Limerick, it saw them come from behind to beat Dublin and Wexford, as well as force a replay in the Leinster final.

Offaly’s chart does not look good. There was no portion in the average game where they had a positive scoring margin. While teams like Dublin, Tipperary and Kilkenny struggled at times, but still looked competitive, Offaly are clearly still very far off the pace right now.

Finally, Wexford’s chart looks fairly strong and steady. They were certainly a strong team this year, but this chart implies stronger results than would be expected after they failed to show up in the quarter final. This chart may be heavily skewed by the fact that two of their games were against far weaker teams, as they beat Offaly by 24 points and Westmeath by 11. With these games to pad out their numbers, it's unsurprising that Wexford’s chart looks so good; in reality, they seemed to plateau somewhat after making big improvements the year before. They were unlucky to lose to Kilkenny, where the fatigue of playing extra consecutive games caught up to them, though this also seemed balanced out by their narrow win over Dublin. They had no trouble with Offaly, but fell apart against Galway and Clare. Wexford’s final position, third in Leinster and defeated at the quarter final stage, felt appropriate, as they scored heavily against weaker team, but struggled against those that were a cut above.

Pythagorean Expectations

One final note on the scoring is the Pythagorean expectation. This was the topic of a previous article, and is a simple measure of how many games you would expect a team to win or lose based on how much they scored and conceded. It can be thought of as a way to measure a team’s luck: some teams scored lots but couldn’t translate it into wins, while others eked out plenty of wins, but always by narrow margins. Though a crude measure, it can be a reliable measure when trying to determine whether a team will be better or worse next year, as luck runs out and the results revert to the mean.

Unsurprisingly, the unluckiest team were Dublin. Though their scores were padded by the Offaly game, it wouldn’t have taken much for them to come away with four wins instead of one. Based on the Pythagorean expectation, they should have won 2, drawn 1, and lost 1 in Leinster; easily enough to put them into third place and through to the knockout stages, and potentially enough for a Leinster final, depending on who the extra win and draw came against.

Overall, the luckiest team was Carlow, who came back to win the Joe McDonagh after starting with a loss to Antrim and unconvincing wins over Kerry and Meath. Their expected score is hurt, however, by their bad loss to Limerick, and in reality, their promotion to Leinster was far from a fluke.

Interestingly, the luckiest team from Munster or Leinster was Limerick, who also had the highest expectation. It just goes to show; even when you’re one of the best, it takes a bit of luck to push you over the line to win a championship. Though they had plenty of convincing wins en route to the championship, both the final and semi final could have gone very differently with only a small swing in score.

Based on the above chart, the teams you’d expect to perform better next year include Dublin, Tipperary, Waterford and Wexford. On the other side of things, Limerick, Galway and Cork are all due for a bit of a drop-off (though Limerick and Galway are still expected to be among the strongest teams). Kilkenny, Clare and Offaly all performed reasonably close to expectation, though Clare and Offaly slightly underperformed and Kilkenny slightly overperformed this year.

Tournament Ratings

The introduction of the new round robin system to begin the tournament resulted in far more competitive matches, and every team that progressed to the knockout stage.felt like they had earned it. However, even with this, a team’s final position in the tournament bracket isn’t always representative of how they performed. The tournament rating is a measure of how each team performed, using a team’s win percentage and the average rating of their opponent to determine their actual performance level. Typically, this would use an Elo rating, though in this case the BAINISTEOIR ratings, the modified-Elo system created for this website, were used.

The tournament rating is the rating that you’d expect a team to have given their performance. It is based entirely off their opponents rating during the competition studied, and doesn’t factor in their own actual rating.

Unsurprisingly, Limerick top the table, with Galway second. Limerick also had the biggest improvement between their actual performance and how they were rated coming into the competition; despite a strong league in 2018, in 2017 Limerick lost their only game in Munster and were knocked out in the first round of last year’s All-Ireland, so winning it all this year was a remarkable turnaround. Galway’s rating isn’t too far behind, as expected for a team with only a slightly worse winning percentage, though the calculations also felt that they had an easier qualification through Leinster than Limerick had in Munster.

Of the two semi-finalists, Cork were considered slightly stronger. This is also unsurprising, as Cork defeated Clare in both of their matches in Munster. Both teams, however, performed above their initial expectation, and finished the All-Ireland with a higher BAINISTEOIR rating than they started with.

Kilkenny and Wexford, the quarter-finalists, are fifth and sixth, respectively. However, both are considered to have performed below expectation. Kilkenny had an especially large drop off, after winning the league earlier in the year.

Carlow are the highest rated team not from Leinster or Munster. Their final rating has them at a performance level of 1841. Though this is a weak rating compared to the contenders, maintaining this rating would currently put them in the range of teams like Dublin, which would be excellent progress for a team without much historical success.

Tipperary had the best performance of any team not to qualify, and the performance closest to the median. However, this was still a huge underperformance; coming into the All-Ireland, Tipperary were the highest rated team, following consistently strong results in recent years (league runners up in 2018 and 2017, semi-finalists and winners in the All-Ireland in 2017 and 2016). They had the biggest underperformance of any team, with a tournament rating 331 points below their rating coming into the All-Ireland. Though they started the All-Ireland as the highest rated team, they finished it in fifth place, behind Galway, Limerick, Clare and Kilkenny.

Offaly had the worst tournament rating of any team in Leinster or Munster, as they failed to pick up even a draw. Their tournament performance puts them below all but two Joe McDonagh teams: Laois, and overall worst-performer Meath.

Of the teams in Munster and Leinster, Wexford performed closest to their initial, though still fell slightly short of their expectation. The overall closest to expectation was Antrim; despite finding themselves in a relegation playoff in the Joe McDonagh, they were still considered stronger than anyone in the group other than the finalists, and perhaps got unlucky with their losses. Their tournament rating was only 7 points lower than their starting rating.

Summary

All in all, the numbers back up the hype: 2018 was an excellent championship. It was higher scoring than any before it, had far more competitive matches than average, and had massive upsets, as teams like Tipperary and Waterford crashed out early, while Limerick went from going winless the year before to winning it all. It was the fifth different winner in six years, and the third from outside the ‘big three’ of Cork, Kilkenny and Tipperary, highlighting how competitive the current era is, especially after years of Kilkenny dominance. Looking at the numbers, such as the pythagorean expectation, or the offensive/defensive ratings, it’s clear that even with so many teams in a position to contend already, next year could have even more.